Electromagnetic pulse

A Type-26 Banshee GSA when hit by the EMP effect of an overcharged plasma pistol.

An electromagnetic pulse (EMP) is the electromagnetic radiation from an explosion (especially a nuclear explosion) or an intensely fluctuating magnetic field caused by Compton-recoil electrons and photoelectrons from photons scattered in the materials of the electronic or explosive device or in a surrounding medium. While organic tissue is unaffected, the resulting electric and magnetic fields may couple with electrical/electronic systems to produce damaging current and voltage surges. The effects are usually not noticeable beyond the blast radius unless the device is nuclear or specifically designed to produce an electromagnetic shockwave. An alternate definition is: a broadband, high-intensity, short-duration burst of electromagnetic energy.

The worst of an electromagnetic pulse generally only lasts for a second, but any unprotected electrical equipment will be affected by the pulse.[1]

The in-atmosphere jumping of the Solemn Penance to slipspace above New Mombasa created a massive electromagnetic pulse that damaged electrical systems in the city, and fried the navigational and safety systems of nearly five dozen SOEIV pods unfortunate enough to drop into the city at that exact moment, plunging them and the Orbital Drop Shock Troopers inside free-falling to near-certain death.[6]

While trying to stop the Didact, Cortana again modified the Master Chief's shields to give off an EMP to disable a carrier wave generator. She referred to it as "taking a page out of our old playbook."[8]

If you disable a vehicle using an EMP, it will show an animation of some sparks flying around, but if you disable it again before it is drivable then the animation will stop and the vehicle will not work.

Some vehicles disabled by an EMP will still have full functionality of its weapons if it has any. For example, if a Warthog is disabled by an EMP, the turret will still be able to turn around and shoot. Likewise, a Banshee, while grounded, will still be able to boost and perform tricks.